Abstract:
The Human Exposure Database System (HEDS) is an integrated database system that contains chemical measurements, questionnaire responses, documents, and other information related to EPA research studies of the exposure of people to Environmental contaminants.

HEDS is a product of the Human Exposure and Atmospheric Sciences Division (HEASD) of the National Exposure Research Laboratory (NERL) which ... is a component of EPA's Office of Research and Development (ORD).

HEDS is a web-enabled data repository for human exposure studies. Its mission is to provide data sets, documents, and metadata for human exposure studies that can be easily accessed and understood by a diverse set of users. Although data are provided about human exposure, HEDS strives to protect the confidentiality of all study participants. HEDS operates in conjunction with the Environmental Information Management System (EIMS), ORD's metadata repository. HEDS provides only data and accompanying documentation from research studies; it does not provide interpretations. It allows a user to download documents for review or data sets for analysis on their own computer system.

Human exposure studies are designed either to describe the level and extent of human exposure to various pollutant sources or to map the relationships between a person's environment and the impact of pollutant sources from that environment. For each study, there is a defined population of interest. It may be the population at hand that is easily accessible for the study, or it may be a broader population from which the study selects a representative sample that may be extrapolated to the larger population. These studies will likely have a survey of the population, whether households, persons, or buildings. (Further references to participants will be generic references to the members or constituents of the population actually being studied.) This survey may be purely demographic in nature, or it can be composed of several questionnaires, each addressing different information about the population.

The information in HEDS is organized as a set of studies each containing data sets, documents, and metadata. There are two documents available for learning how to use HEDS. One document is for First Time Users and provides a step-by-step approach for learning the basic functions in HEDS. The other document is a Reference which describes the functions and file formats available through HEDS.

Access Constraints
For users with accessibility needs, HEDS provides an alternate approach for retrieving and viewing data available in HEDS. These users can download the complete data set package for a data set of interest and view, customize, and use the data and associated metadata with their own software. Each Complete Data Set package is zipped and includes files with the data, data dictionary, and code set for the complete data set.

Use Constraints
The EPA does all it can to ensure the identity of individual survey participants cannot be disclosed. All direct identifiers, as well as any characteristics that might lead to identifications, are omitted from the data. Any intentional identification or disclosure of a person or establishment violates ... the assurances of confidentiality given to the providers of the information. Therefore, users will (1) use the data in this study for statistical reporting and analysis only; (2) make no use of the identity of any person or establishment discovered inadvertently and will advise the HEDS Administrator of any such discovery; (3) will not link this data with individually identifiable data from other EPA or non-EPA data.